feat: establish reproducible FreeCAD web compatibility baseline

scripts/fetch-freecad-source.mjs

@@ -24,4 +24,9 @@ git('-C', target, 'fetch', '--depth=1', 'origin', `refs/tags/${toolchain.source.
 const fetched = git('-C', target, 'rev-parse', 'FETCH_HEAD')
 if (fetched !== toolchain.source.commit) throw new Error(`Fetched FreeCAD tag resolved to ${fetched}, expected ${toolchain.source.commit}.`)
 git('-C', target, 'checkout', '--detach', toolchain.source.commit)
+// The locked source graph includes GSL, OndselSolver, AddonManager and the
+// test support checkout. Initialize every gitlink so a clean oracle build does
+// not silently fall back to a partial module set.
+git('-C', target, 'submodule', 'sync', '--recursive')
+git('-C', target, 'submodule', 'update', '--init', '--recursive')
 console.log(`FreeCAD source ready: ${target} @ ${toolchain.source.commit}`)